The family Girellidae, or blackfish, comprises only one genus with ten species worldwide. Often grouped with the drummers the blackfish have more dorsal fin spines and a different arrangement of teeth. The zebra fish can be easily identified by nine or ten tapering black vertical bars atop a white background, with yellow fins. Juveniles are darker with less distinct barring. The zebra fish has a small mouth, a dorsal fin extending down the length of the body to the tail fin and a forked caudal (tail) peduncle. The species grow to a maximum length of 54 cenitmetres, though are often not seen larger than 40 centimetres.
The zebrafish is endemic to temperate Australian waters, from Jurien Bay, WA to Sydney, NSW and northern Tasmania. They occupy various rocky reef habitats in shallow waters to 20 metres depth, with small juveniles commonly occurring in rock pools on reef flats and adults forming small to moderate schools near reefs with ledges for shelter.
Occurrence at the Busselton Jetty:
The zebrafish is a occasional visitor to the underwater observatory, with a few individuals having been sighted.